A bus bar is a multilayer device that is commonly used for power and/or signal distribution in electronic systems and power conversion equipment. Bus bars generally include at least two conductors (usually in the form of elongated strips or bars of a metal conductor such as copper) separated by an insulating layer made of, for example, a dielectric material. The conductors typically have a number of distribution pins extending therefrom which enable electrical connections to be made between the conductors and the remainder of the circuit components.
FIG. 1 is a cross-sectional view of a portion of a prior art bus bar assembly 2. Bus bar assembly 2 includes a first main conductor 4 made of, for example copper, a second main conductor 6 also made of, for example copper, and an insulator layer 8 made of, for example, a dielectric material, provided between the first main conductor 4 and the second main conductor 6. Typically, air 10 is trapped in small air voids that exist between first main conductor 4 and insulator layer 8 and between second main conductor 6 and insulator layer 8. Air 10 in the air voids frequently leads to a plasma creation in the air voids known as partial discharge. The Partial discharge is problematic as it slowly breaks down the material of insulator layer 10. The partial discharge effect is caused by the high field strength that is used in a dielectric insulator, and is exacerbated by the relative dielectric constant of insulator layer 8 as compared to the dielectric constant of air 10, which causes the field to concentrate in the small air voids. While this does not lead to an arc, it does lead to the plasma creation known as partial discharge.
There is thus a need for a bus bar assembly that decreases the likelihood of the occurrence of partial discharge in the bus bar assembly.